ANTARES  (ALPHA (α) SCORPII)
RED SUPERGIANT STAR

Right Ascension:
16h 29m 24s

Best Seen:
7/15 - 9/15

Declination:
-26º 25' 55"

Magnitude:
1.06

Computer File:
antares

Constellation:
Scorpius

Actual

Compared to Sun

Distance

604 l.y.

--

Actual Brightness

--

10,100

Surface Temperature

5,900 ºF

0.6

Diameter

~ 500 million miles

575

Mass

--

15-18

Surface Gravity

--

--

Surface Composition (by mass)

74% hydrogen 24% helium 2% everything else

same

Spectral Type

M1 Ib

--

Density (gram/cubic cm)

--

--

WHAT TO LOOK FOR THROUGH THE TELESCOPE:

  1. Recommended eyepiece: 24mm or 40 mm.

  2. When people look through the telescope a bright reddish-orange point of light should be seen.

ANTARES INFORMATION:

  1. Antares is the 11th brightest star in the Northern Hemisphere’s night sky (16th brightest if including the Southern Hemisphere’s nighttime stars.

  2. This is probably the second largest of the bright stars in the sky. (Betelgeuse is larger).

  3. Antares has a companion:

a. Magnitude: 6.5

b. Luminosity: 50 times that of the sun.

c. Spectral Type: B2.5

d. Separation: 45 billion miles (500 times Earth-Sun distance)

e. Period: 853 years

Item
Updated Notes

Coordinates 01-06-2003
tweaked a bit

Magnitude
01-06-2003

05-19-2005
previously: 0.92 – BUT this matches with Scott’s The Flamsteed Collection and SIMBAD Crosschecked. studies vary from +0.92 to 1.1 so number OK.

Distance
01-06-2003

05-19-2005
previously: 520 – BUT this matches with Flamsteed and SIMBAD OK. Croschecked with paper Krudrizki &Reimers, 1978, Astron. And Astrophys. Vol 70 p.227 Their numbers: 180 pc, SIMBAD -185 pc

Actual Brightness
01-06-2003
previously 9,000 – BUT this matches with Flamsteed

Surface Temperature 01-06-2003

05-19-2005
supported by http://www.astro.uiuc.edu/projects/sow/antares.html Croschecked with paper Krudrizki &Reimers, 1978, Astron. And Astrophys. Vol 70 p. 227. They have 3,550k which comes out to 5,900F

Diameter
01-06-2003
previously 600 million miles / 700 times sun – BUT site says over 4 AU’s http://www.astro.uiuc.edu/projects/sow/antares.html

Changed from 740 million miles and 860 Suns. No book or net source agrees with this high number. Croschecked with paper Krudrizki &Reimers, 1978, Astron. And Astrophys. Vol 70 p. 227. They have 575times the Radius of the Sun.

Mass
01-06-2003

05-19-2005
10-15 -cannot find support for this, but looks ok? Croschecked with paper Krudrizki &Reimers, 1978, Astron. And Astrophys. Vol 70 p. 227. They have 18 solar masses. So I compromised.

Surface Gravity

Surface Composition 01-06-2003
OK for all stars

Spectral Type
01-06-2003
OK with SIMBAD and Flamsteed

Density 01-06-2003
previously: <10-6 – BUT can find no support

Other Information
01-06-2003
can’t confirm luminosity, separation, or period, but looks OK brightness rank from Hipparcos site